No, the compound noun 'sand dune' is a concrete noun, a word for a physical thing.
An abstract noun is a word for something that can't be seen, heard, smelled, tasted, or touched.
The word "dune" is a noun. It refers to a mound or ridge of sand formed by the wind, typically found in deserts or along the coast.
the top of a sand dune is called the crest of the dune.
A hill of sand in a desert is normally referred to as a dune
A sand dune is a landform, not a climate.
A sand dune is the deposition of windblown sand.
A sand dune is a pile of wind-blown sand.
A sand dune that got blown away
A sand dune is a Constructive force.
A Sand Dune, more specifically a "Seif Dune" or a "Barchan Dune".
small hill of sand caused by the action of wind
It is a sand dune that is formed at right-angle to the prevailing wind.
crescentic dune linear dune star dune dome dune parabolic dune